Electric lamp



00%. 18, 1949. A BURCHARD 2,485,429

ELECTRIC LAMP Filed Jan. 11, 1946 0 .9 6 0 '7 3 4 INVENTOR.

HTTa/F/VEK Patented Oct. 18 1 949 ELECTRIC LAMP Alonzo H. Burchard, St. Claire Shores, Mich., assignor to Briggs Manufacturing Company, Detroit, Mich., a corporation of Michigan Application January 11, 1946, Serial No. 640,618

3 Claims. (Cl. 240-218) This invention relates to an improved electric lamp and especially to a lamp of the portable type which, although adapted for a Variety of purposes, finds particular use in connection with the inspection of painted or lacquered surfaces, such as those of automobile bodies, in order to reveal blemishes, off-color areas or imperfections in the finished surfaces.

During the inspection of painted or lacquered surfaces such, for example, as motor vehicle body panels it is necessary that a lamp of relatively high candle power he used to reveal any blemish or imperfection that might have occurred during the painting of the panels. The high powered lamp necessarily used generates considerable heat in operation and thus creates an element of danger, particularly when the lamp is used in restricted spaces where the accumulated fumes of paints and lacquers become highly inflammable. Present lamps used for paint inspection in paint booths or similarly restricted spaces require the manual operation of a switch to disconnect the electric current when the lamp is not in use. Carelessness on the part of a paint inspector in not disconnecting the current when the lamp is not in use presents a definite hazard of explosion and fire which may cause severe personal injury and property damage.

It is an object of the invention to provide an improved electric lamp for use in the inspection of painted surfaces and which is provided with means for automatically disconnecting the electric current when the lamp is not in use for inspection or other purposes.

Another object of the invention is to provide an improved electric lamp which is provided with an automatic device adapted to interrupt the flow of electric current to the lamp when it is held or set down in a substantially vertical position. p}

A further object of the invention is to provide an improved electric lamp for usein restricted spaces wherein combustible fumes or gases accumulate, and wherein means in the form of a mercury switch is provided for automatically disconnecting the flow of electric current to said lamp when the lamp is positioned in predetermined manner, such as in a vertical or upright position.

Other objects of this invention will appear in the following description and appended claims, reference being had to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views.

Fig. 1 is a side elevation in section illustrating a lamp embodying the present invention.

Fig. 2 is a side view, partly broken away, and showing an operative position of the lamp.

Before explaining in detail the present invention it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

The lamp as illustrated in the drawings comprises a tubular holder H which may be formed of metal or other suitable material such as rubber or plastic material. The holder ll provides a hand grip enabling the lamp to be easily grasped in the hand by the operator.

A reflector I4 is attached to the holder II at one end thereof, and for this purpose the holder II is provided with a thread l2 which is adapted to engage a threaded extension l3 of the reflector [4 to secure the shell and reflector together. The reflector I4 is of conventional design being generally convex in shape and is provided at. its outer edge with an embossed rim IS. The rim I5 is shaped to hold a glass or lens [6 which is secured in place within the rim by a split metallic ring I! which fits into a circular groove I5a in the rim l5.

Mounted. within the holder II at opposite ends thereof are insulating members or plugs l8 and 24 formed of any suitable non-conductive or insulation material such as rubber or porcelain. The plug H3 at the lower end of the holder I1 is formed with a threaded recess or socket I! having two spaced metallic contact points 2! and 22 suitably located within the base thereof. The socket l 9 is threaded to receive the threaded end of a light bulb 20. The bulb 20 is provided with spaced metallic contact points 23 and 24a which are adapted to engage the points 2! and 22 when the bulb is fully extended into the recess. It should be noted in this connection that any conventional type of bulb and socket arrangementprovided at its outer end with a recess 25. A

Standard male plug comprising pins or prongs 3 26 and 21 is secured in conventional manner within the recess 25. The pins 26 and 21 of the plug are adapted to be inserted into live openings in a female plug 28 to permit the conduction of electric current through the pins from a power outlet by means of the wires 30 and 3|.

The flow of electric current within the holder II to the bulb 20 is accomplished by means of conductors and a mercury switch connecting the pins 26 and 2'! with the contact points 2i and 22. A wire 32 is attached at one end to the pin 26 by means of the screw 33 and at its other end is fixed as by soldering to the contact point 2|. A wire 34 is connected at one end to the pin 2'1 by means of a screw 35 and at its opposite end is connected to one end of the mercury switch 36 by means of a screw 31. A wire 38 is secured at one end to the opposite end of the mercury switch by means of a screw 39 and at its opposite end the wire is fixed as by soldering to the contact point 22.

The mercury switch 36 is of conventional construction and comprises a sealed container made of a suitable insulating material such as glass or rubber. The container is partially filled with fluid mercury 40 which is a highl efficient conductor of electric current. It is to be understood, however, that any suitable fluid which readily conducts electricity may be used in place of the mercury. It is also a fact that other conventional types of automatic switches or circuit breakers may be used in place of the fluid actuated switch shown without departing from the concept of the invention. The container of the switch 36 is held in position Within the holder II by means of a spring metal collar or clip 4| which is secured within a recess 42 formed in the inner end of the insulating member 24.

In operation when the lamp is held in a substantially horizontal position, as shown in Fig. 2, the mercury 46 within the switch 36 contacts both of the metallic screws 3'1 and 39, thus effecting a continuous flow of electric current to the bulb 20. When the lamp is placed in a substantially vertical position as shown in Fig. 1, the mercury within the sealed container contacts only the screw 31, thus breaking the circuit and interrupting the flow of electric current to the bulb.

When an inspection lamp of the above construction is used in-a paint booth or similar restricted space the normal position of the lamp when not in use is with the rim of the reflector resting upon the floor. When the lamp is in this position it is difficult to determine whether or not the current has been disconnected since the bulb is hidden from view and light therefrom cannot easily be seen. Where a manually operated switch is used with a lamp of the above type, or where it is necessary for the operator to disconnect the electric power some distance from the lamp, carelessness may result and sub sequent heat generated from a lamp left burn- .ing may cause the ignition of highly inflammable I claim:

1. An electric lamp comprising a holder forming a hand grip, an electric light bulb supported by said holder, a convex reflector mounted on said holder around the bulb and terminating in an annular rim spaced outwardly of said bulb to permit the lamp to be supported upon said rim with the bulb directed downward and sub stantially concealed by the reflector, conducting means within said holder for conducting electric current to and from said bulb and including a mercury switch adapted to conduct the current therethrough when the lamp is in horizontal position and to interrupt the flow of said current when the lamp is supported upon said rim as aforesaid.

2. An electric lamp comprising a holder form- I ing a hand grip, an electric light bulb supported "by said holder, a convex reflector mounted on said holder around the bulb and terminating in an annular rim spaced outwardly of said bulb to permit the lamp to be supported face down upon said rim, conducting means within said holder for conducting electric current to and from said bulb and including a container having contacts spaced in the direction of the principal axis of the reflector and also including a body of mercury within the container adapted to electrically connect said contacts when the lamp is in horizontal position and to disconnect said contacts when the lamp is supported upon said reflector as aforesaid with the light bulb directed downwardly and substantially concealed by the reflector.

3. An electric lamp comprising a holder forming a hand grip, an electric light bulb supported at one end of said holder, a convex reflector mounted on said end of the holder and terminating in an annular rim spaced outwardly of said bulb to permitthe lamp to be supported in inverted position with the rim of the reflector resting upon a horizontal surface and the holder extending upwardl therefrom, conducting means for conducting electric current through said holder from the outer end thereof to said bulb, said conducting means including a container mounted within said holder having contacts within the container spaced longitudinally of the principal axis of the reflector and also including a body of mercury in the container adapted to electrically connect said contacts when the lamp is in horizontal position and to disconnect said contacts when the lamp is supported in said inverted position with the bulb directed downwardly and substantially concealed within the reflector.

ALONZO H. BURCHARD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS France June 4, 1918 

